Cages of roller bearings are usually rotationally symmetric components that are normally made by stamping or injection molding for medium and high production volumes and by turning and milling for low volume production or if high strength and/or special materials are required. In the latter case, manufacturing starts typically with a tube material that is then turned to the right dimension. The receiving pockets of the cage are then machined.
This classical production technology means however, that any additional removal of material which is not needed for the strength of the cage (for example to reduce weight) increases production time and cost. If the material is at a location which cannot be reached by a turning or milling tool, it cannot be removed.
Despite the fact that this material is not needed and removed later it must still be paid for and thus causes cost. Hence the raw material cost is higher than necessary with respect to the required strength of the cage.
For applications that are not weight-sensitive the machining time is thus minimized and extra weight is accepted.
It is an object of the present invention to develop a cage and a method for its production which allow overcoming the mentioned drawbacks. Thus, it should become possible to obtain a cage in a cost efficient manner which is light but has the required strength and stiffness. Consequently, the required material should be minimized and located only at those regions where it is necessary to carry the load without relevant deformations of the cage.